Best Hydronic Heat Pump Australia | Maxa vs Viessmann vs Immergas

Maxa vs Viessmann vs Immergas heat pumps for Australian conditions

Most installers carry one brand and recommend it for everything. AHHAC is authorised for all three of the major Italian and German hydronic heat-pump makers — so this comparison is genuinely independent. Here's how Maxa, Viessmann and Immergas stack up on COP, refrigerant, output, cold-climate performance and warranty.

Reviewed by AHHAC Technical Team · Updated 14 October 2026

At-a-glance comparison

	Maxa i-290 / i-32V5	Viessmann Vitocal	Immergas Magis
Origin	Italy	Germany	Italy
Refrigerant	R290 (GWP 3)	R290 (GWP 3)	R32 (GWP 675)
Heating COP	Up to 4.94	Up to 4.15 (DHW)	Up to 4.5 SCOP
Output range	6 – 27 kW	DHW 200–270 L	4 – 30 kW
Functions	Heat · Cool · DHW · Chilled	Domestic hot water	Heat · Cool · DHW
Hot water max	78 °C	70 °C	65 °C
Cold-climate rating	−25 °C ambient	−15 °C ambient	−15 °C (hybrid option)
Hybrid (HP + gas)	No	No	Yes (Hercules Pro)
AU distributor	Next Cycle	Next Cycle	Hunt Heating
Warranty (domestic)	Up to 7 yr	5 yr parts & labour	Up to 5 yr
Best for	All-in-one, low-GWP	Premium DHW, German build	Retrofits, cold-climate hybrid

Figures are indicative best-case manufacturer ratings; AHHAC sizes and quotes to your specific heat-loss calculation.

Maxa

Best all-in-one, lowest GWP

The Maxa i-290 R290 monoblock does four jobs from one outdoor unit — heating, cooling, domestic hot water and chilled water — at the highest heating COP in this group (4.94) and the lowest-GWP refrigerant available. It's the only R290 monoblock on Queensland's Type B Gas Device Register and is rated to −25 °C, making it our default pick for all-electric new builds and cold-climate sites. The R32 sibling, the Maxa i-32V5, gives 11 chassis sizes if R32 support is preferred.

→ Maxa i-290 heat pump → Maxa i-32V5 heat pump

Viessmann

Premium DHW, German engineering

Viessmann's Vitocal 161-A is the benchmark domestic-hot-water heat pump — R290, COP 4.15, around 70% energy savings versus electric storage, with the polished ViCare app and German build quality. Where the brief is specifically efficient domestic hot water (rather than whole-home space heating), Vitocal is the standout. For space heating Viessmann also offers the Vitodens 100-W condensing gas boiler, so the brand can cover hybrid electrification paths.

→ Viessmann Vitocal 161-A → Viessmann Vitodens 100-W

Immergas

Retrofit & cold-climate hybrid

Immergas Magis is the retrofit specialist — 4 to 30 kW across single and three-phase, designed to drop onto an existing radiator or underfloor network. Its trump card is the Magis Hercules Pro hybrid, which pairs a heat pump with a condensing gas boiler and switches fuel automatically based on outdoor temperature — ideal for Canberra, the Blue Mountains and the cold Melbourne fringe where a pure heat pump struggles on the coldest mornings.

→ Immergas Magis heat pump → All hydronic heat pumps

How AHHAC chooses between them

Because we're an authorised installer for all three, the decision comes down to your project — not our supplier agreement. The starting point is always a heat pump hydronic heating heat-loss calculation, then we weigh four things:

1. Climate. Mild Sydney and Brisbane loads suit any of the three; cold Canberra, Blue Mountains and the Melbourne fringe push us toward the −25 °C-rated Maxa i-290 or the Immergas hybrid. See the local data on our Canberra and Melbourne pages.

2. New build vs retrofit. New builds get the all-in-one Maxa; retrofits onto existing radiators or underfloor often go to Immergas Magis for its drop-in compatibility.

3. Hot water priority. If efficient domestic hot water is the main driver, the Viessmann Vitocal is hard to beat — see our domestic & commercial hot water options.

4. Future-proofing. For clients who want the lowest-GWP refrigerant and longest regulatory runway, R290 (Maxa i-290, Viessmann Vitocal) wins over R32.

For the full cost, COP and brand breakdown, read our guide to heat pump hydronic heating in Australia.

Why system design matters more than the heat pump brand you choose

After installing all three brands, our honest view is that the badge on the outdoor unit rarely decides whether a home ends up comfortable and cheap to run. A well-designed system on any of these brands will outperform a poorly designed system on the “best” one. Here's what actually moves the result.

Flow temperature. Every heat pump in the table is more efficient at lower water temperatures. A home designed around underfloor at 35–45 °C, or generously sized radiators, gives any of them an easier job than one forced to run hot all winter.
Correct sizing. An oversized unit short-cycles; an undersized one leans on backup heat. Both cost more to run. Sizing from a room-by-room heat-loss calculation, not floor area, matters more than a few points of rated COP.
Commissioning. Air purged, flow rates set, heating curve tuned to the house — skipped steps here explain many of the “my heat pump is expensive to run” calls we get about other installers' work.
Service support. Maxa and Viessmann come through Next Cycle, Immergas through Hunt Heating. Local parts and an installer who services what they install protect your warranty years down the track.
Controls and zoning. Sensible zones and schedules, rather than dozens of tiny zones calling for heat separately, let any heat pump run the long, steady cycles it is most efficient at.

One nuance on the comparison itself: the Viessmann Vitocal 161-A is a domestic hot water heat pump, so for whole-home space heating the real choice is usually Maxa versus Immergas, with a Vitocal sometimes added alongside for hot water.

Climate shifts the answer too. In Sydney and Brisbane all three are comfortable choices; on frosty sites we lean towards the cold-rated options. See the results from our Canberra cold-climate heat-pump retrofit, local advice on heat pump hydronic heating in Sydney, or narrow down the Maxa choice with our Maxa i-290 vs i-32V5 guide.

Written from on-site experience by the AHHAC Technical Team.

Licensed, in-house hydronic engineers — since 1998.

AHHAC's in-house design and service team — licensed plumbers and hydronic engineers (Lic 262528C) who have designed and installed 2,400+ hydronic heating, cooling and hot water systems across Australia since 1998.

We only specify equipment after a heat-loss and system-compatibility check, then supply, install and commission it with our own licensed plumbers to AS/NZS 3500 (plumbing) and AS/NZS 5601 (gas), register the manufacturer warranty and service it for the life of the system.

Sized from a heat-loss & compatibility check

Authorised Maxa, Viessmann & Immergas supplier

Supplied, installed & commissioned in-house

Manufacturer warranty registered for you

Six showrooms: NSW · ACT · VIC · QLD

Spare parts & servicing after install

Heat pump comparison — FAQ

Which is the best hydronic heat pump for Australian conditions — Maxa, Viessmann or Immergas?+

There's no single winner — it depends on the job. For the lowest-GWP all-in-one (heating, cooling, hot water and chilled water from one outdoor unit), the Maxa i-290 R290 leads. For premium German engineering and the best domestic-hot-water heat pump, Viessmann Vitocal wins. For retrofit-friendly installs and hybrid heat-pump-plus-gas flexibility in cold climates, Immergas Magis is the pick. AHHAC is authorised for all three, so our recommendation is genuinely independent.

Does AHHAC really carry all three brands?+

Yes — AHHAC is an authorised supplier and installer of Maxa, Viessmann and Immergas hydronic heat pumps. Most installers carry only one brand and recommend it for every job; because we carry all three, we spec whichever genuinely suits your home, climate and budget.

What's the difference between R290 and R32 refrigerant?+

R290 (propane) is a natural refrigerant with a global warming potential of just 3 — the lowest available — and it's slightly more efficient at high flow temperatures. R32 has a GWP of 675 (still far lower than the old R410A at 2,088) and is very widely supported. The Maxa i-290 and Viessmann Vitocal use R290; the Maxa i-32V5 uses R32. For future-proofing against refrigerant phase-down, R290 is the safer long-term choice.

Which heat pump is best for a cold climate like Canberra or the Blue Mountains?+

For sustained sub-zero conditions we usually spec the Maxa i-290 (rated to −25 °C ambient) or the Immergas Magis Hercules Pro hybrid, which switches automatically between heat pump and a condensing gas boiler when the heat-pump COP drops below economic. Both keep running efficiently through frost mornings where a standard metro-grade heat pump would struggle.

Which has the best warranty?+

Maxa offers up to 7 years on domestic applications; Viessmann offers 5 years parts and labour on the Vitocal DHW heat pump; Immergas offers up to 5 years when registered with Hunt Heating. AHHAC adds a workmanship warranty on top of the manufacturer cover for all three, and our annual service contracts keep the manufacturer warranty valid.

Not sure which heat pump suits your home?

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